Water treatment device

ABSTRACT

A water treatment device, having a housing with duct areas which are used to conduct the water to be treated. At least a first and a second electrode are accommodated in the housing. The first and second electrodes are alternately positive-poled and negative-poled. Electro-conductive material is introduced into the housing. In order to provide a water treatment device which can be operated on a permanent basis with a high degree of efficiency, the first and second electrodes are arranged in separate first and second electrode chambers which are insulated from each other by one or several insulating bodies, the electrode chambers are respectively filled with a bulk material of a uniform granulated material, and the insulating bodies are pervious to water to be treated but are impervious to the granulates forming the bulk material.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a device for treating water, having a housing with conduit areas for conducting the water to be treated, wherein at least one first and one second electrode is arranged in the housing, the first and second electrodes are alternatively positively and negatively polarized, and an electrically conductive bulk material is placed into the housing.

[0003] 2. Discussion of Related Art

[0004] A conventional device is known from PCT International Publication WO 98/16477. This device is used for reducing, or preventing, the formation of scale in aqueous solutions. A housing is used, into which a cartridge is inserted. The cartridge has two electrodes, each of which is arranged in an electrode chamber. A bipolar electrode is arranged in the area between the electrodes, which is embodied as a fixed bed. The fixed bed is formed by a bulk material which has electrically conducting carbon particles and non-conducting insulating particles, for example pebbles, glass or plastic bodies. The non-conducting insulating particles insulate the carbon particles from each other, so that the formation of short circuits is prevented. A voltage is applied to the bipolar electrode via the electrodes. During this the individual carbon particles are given a positive and a negative charge. The liquid to be treated is conducted through the bipolar electrode. The calcium contained in the liquid is precipitated in the form of calcite at the negative pole areas of the carbon particles. To prevent a calcite deposit in this pole area, the polarity of the electrodes is regularly reversed.

[0005] An even blending process in the bipolar electrode, and therefore the even distribution of the conducting and non-conducting particles, is important for this known arrangement. However, in actual use it has been shown that a segregation occurs in the bipolar electrode, for example in connection with its transportation or partially during its operational use. It then loses its effectiveness and the efficiency is drastically reduced.

SUMMARY OF THE INVENTION

[0006] It is one object of this invention to provide a device of the type mentioned above but which can be operated long term at high efficiency.

[0007] This object is achieved with the first and second electrodes housed in first and second electrode chambers, which are separated from each other and are electrically insulated from each other by one or several insulating bodies. Each of the electrode chambers is filled by bulk material of a uniform granulate, and the insulating bodies are permeable to the water to be treated, but impermeable to the granulated bulk material. Polarized areas are created in the electrode chambers, in which a single fixed polarization exists for a defined length of time. With this division into unipolar areas, the homogeneously composed bulk material of this invention can be used, wherein a segregation as in the prior art is not a problem. It is thus possible to assure dependable operation because of this combination of characteristics.

[0008] The bulk material can include, for example, granulated carbon, in particular activated charcoal, which is introduced into the electrode chamber in the form of a fixed bed.

[0009] In accordance with a preferred embodiment of this invention the insulating bodies are formed as bulkhead walls and have a screen-like passage area for the water to be treated, wherein the sizes of the openings forming the passage areas are less than the granule diameters of the particles of the bulk material.

[0010] In order to achieve the greatest possible flow introduction into the bulk material, the first and second electrodes can be embodied rod-like and can be surrounded over their entire length by the bulk material.

[0011] In one embodiment of this invention, a conduit area which is surrounded by an area which receives the electrode chambers is arranged in the housing. The conduit area is in spatial connection with the electrode chambers via the openings, and the side of the electrode chambers which faces away from the conduit area in the radial direction is covered by a liquid-permeable shell. A conduit section adjoins the shell in the housing. In this case, the conduit area can be selected such that initially the water to be treated is introduced through the central conduit section and then flows through the electrode chambers and the peripheral conduit area. However, a reverse flow is also conceivable. A re-mixing of the electrolysis products resulting from the treatment is avoided with these types of flow conduction.

[0012] A device in accordance with this invention is distinguished because the electrode chambers are separated from each other by insulating bodies which substantially extend in the flow direction of the water to be treated. In this case the liquid to be treated flows parallel through the individual electrode chambers.

[0013] It is also possible to connect the electrode chambers in series so that they are separated from each other by insulating bodies extending transversely with respect to the flow direction of the water to be treated, and the electrode chambers are arranged one behind the other in the flow direction.

[0014] A combination of parallel and series connection is also conceivable.

[0015] For preventing an impermissible nitrite formation in the water, in a further embodiment of this invention, viewed in the flow direction, an oxidation zone, through which the water treated in the associated electrode chamber, or in several electrode chambers is conducted, is arranged behind at least one of the electrode chambers. A fixed bed electrode which, for example, includes carbon particles and has a positive polarity, can be connected downstream as the oxidation zone.

[0016] A calcite precipitation takes place only near or in the area of the negatively polarized electrode chambers during the operation. For achieving the greatest possible efficiency, a device in accordance with this invention can be designed so that different volume flows of the water to be treated flow through the electrode chambers of different polarization. Alternatively, or additionally, the length of polarization of the cathodic and the anodic phases of at least one of the electrodes is selected to be different. In this case the water to be treated remains longer in the electrode chamber with negative polarization.

[0017] For achieving the greatest possible even flow density in the electrode chambers, a device can be designed so that the electrodes are arranged at least partially concentrically with respect to the conduit area arranged in the housing. The electrodes, which are arranged on a graduated circle around the conduit area are distributed equidistantly with respect to each other in the ambient direction. For achieving an improved calcite crystal formation, the water to be treated flows through a magnetic treatment device prior to entering the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] This invention is explained in greater detail in view of embodiments shown in the drawings, wherein:

[0019]FIG. 1 shows a device for the treatment of water in a lateral view and in vertical section;

[0020]FIG. 2 shows the device in FIG. 1 but in horizontal section; and

[0021]FIG. 3 is a horizontal section taken through another embodiment of a device for the treatment of water, which differs from FIGS. 1 and 2.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0022] A device, for the treatment of water, which has a tube-shaped housing 25 is shown in FIG. 1. In its bottom area, the tube-shaped housing 25 is closed off by a support 10. The support 10 has a flange plate 11 which is in contact with the lower front face of the housing 25. The flange plate 11 forms a collar 12, on which the front face of the housing 25 is seated. A seal 13 is arranged near or in the area of the collar 12. The seal 13 seals the interior of the housing 25 against the surroundings. In the area adjoining the collar 12, the support 10 has a shoulder 14. The shoulder 14 is used for receiving a tube-shaped shell 23. The tube-shaped shell 23 is centered and aligned on a cylindrical protrusion 15 of the support 10. The protrusion 15 projects into the interior surrounded by the shell 23. A conduit section 20 is arranged in the center of the shell 23 and is the form of a tube. In its casing, the conduit section 20 has a plurality of openings. The conduit section 20 is maintained on a blind bore 18 of the support 10. As shown in FIG. 2, four electrodes 22.1, 22.2 are arranged in the area between the conduit section 20 and the shell 23. In this case the electrodes 22.1, 22.2 are arranged concentrically with respect to the conduit section 20, and each is offset by 90° from the other. The support 10 has electrode seats 17 in the form of bores for fixing the electrodes 22.1, 22.2 in place. Contacting the electrodes 22.1, 22.2 takes place via contact springs 19.2, which are inserted in a threaded receiver 16 which terminates in the electrode seat 17. A contacting element 19.1 is screwed into the threaded receiver 16 and presses the contact springs 19.2 against the electrodes 22.1, 22.2 and can be connected to a power supply on the exterior of the housing 25. The remaining annular space between the conduit section 20 and the shell 23 is filled with a bulk material of electrically conductive material, for example activated charcoal. As mentioned above, the conduit section 20 has openings and is therefore embodied in a screen-like manner. The shell 23 is also embodied in a screen-like manner. The openings of the screens are of such a size that the particles of the bulk material cannot leave the space between the shell 23 and the conduit section 20, but that an electrical insulation between the adjoining areas is assured.

[0023] As FIG. 1 further shows, a cap 30 is pushed on the head of the shell 23. The cap 30 has a shoulder 33 for this purpose, which receives the front face of the shell 23. Furthermore, the cap 30 has electrode seats 34, which are embodied in the manner of a blind bore and in which the ends of the electrodes 22.1, 22.2 are received. A conduit section 36 passes through the center of the cap 30 and terminates in a widened seat 35. The end of the conduit section 20 is received in the seat 35. On its side facing away from the conduit section 20, the cap 30 has a shoulder 31, on which a cover 40 is sealingly held by a seal 32. The cover 40 encloses an outer chamber 41, which is spatially connected with a conduit area 24 formed between the housing 25 and the shell 23. The cover 40 has an inner chamber 42, which is spatially connected with the conduit section 36 of the cap 30.

[0024] For assembling the device, first the support 10 is inserted into the housing 25 and is fastened in a suitable pressure-proof manner. Then, the shell 23, the electrodes 22.1, 22.2 and the conduit section 20 are fastened on the support 10 from the direction of the top of the housing 25. Thereafter the bulk material can be inserted. Finally, the cap 30 is inserted into the housing 25 on the cover side. Now the open top of the housing 25 can be closed with the cover 40.

[0025] As shown in FIG. 1, the cover 40 has a circumferential flange 43. The flange 43 rests on a radially outward oriented rim 37 of the housing 25, with a seal 44 placed between them. A screw ring 45 is used for connecting the cover 40 with the housing 25. An interior thread 47 of the screw ring 45 can be screwed on an exterior thread of the cover 40. In this case the screwing-on movement is limited by a detent 46 of the screw ring 45, which contacts the underside of the rim 37.

[0026] As FIG. 2 shows, the space between the conduit section 20 and the shell 23 is divided into four electrode chambers 21.1, 21.2. An electrode 22.1, 22.2 is arranged in each of the electrode chambers 21.1, 21.2. The division of the electrode chambers 21.1, 21.2 takes place by insulating bodies 50, which are embodied as a bulkhead wall. These insulating bodies 50 are permeable to liquid media, in particular aqueous solutions. But the insulating bodies 50 are impermeable to the granules of the bulk material. On their radial ends, the insulating bodies 50 are fixed in place in seats 51 of the shell 23, or of the conduit section 20. The seats 51 prevent a displacement of the insulating bodies 50 and they dependably prevent an electrically conducting connection between the individual electrode chambers 21.1, 21.2.

[0027] During operation, water to be treated is fed to the device shown in FIGS. 1 and 2 via the inner chamber 42 of the cover 40. The water then flows through the conduit section 36 to the conduit section 20. In this case the water flows in the radial direction through the shell 23 of the conduit section 20. Thereafter, the water reaches the electrode chamber 21.1, 21.2. Each of the adjacently located electrode chambers 21.1, 21.2 is differently polarized. Accordingly, the electrodes 22.1 can be positively charged, the electrodes 22.2 can be negatively charged. A calcite precipitation out of the water to be treated then occurs in the area of the negatively charged electrode chambers 21.2. In the process, the calcite is deposited on the individual carbon particles of the bulk material. A change in polarization occurs after a defined period of time. The electrodes 22.1 are negatively polarized, the electrodes 22.2 positively. Because of the polarization reversal, the calcite deposits at the carbon particles are removed and are floated out like germs. The treated water leaves the electrode chambers 21.1, 21.2 through the shell 23 in the radial direction. There, it flows to the conduit area 24 and can then be fed into a water main network via the outer chamber 41 of the cover 40. The above described flow direction can be reversed, so that the water to be treated is first supplied to the outer chamber 41. In that case the water leaves the device through the inner chamber 42.

[0028] In the embodiment of this invention as shown in FIGS. 1 and 2, the flow passes parallel through the electrode chambers 21.1, 21.2. It is possible to provide a series connection of the electrode chambers 21.1, 21.2. Such an arrangement is shown in FIG. 3. Here, a ring-shaped insulating body 50, which is arranged concentrically in relation to the conduit section 20 and the shell 23, is used in place of the radially arranged insulating bodies 50. Two electrode chambers 21.1, 21.2, which are embodied in a ring shape, are thus formed. Respectively four electrodes 22.1, 22.2 are arranged in the individual electrode chambers 21.1, 21.2. The same as in the embodiment shown in FIG. 1, the individual electrodes are again arranged offset by 90° from each other. Based on this arrangement of the electrodes 22.1, 22.2, an optimal and even flow density is achieved within the individual electrode chambers 21.1 and 21.2.

[0029] In the embodiment shown in FIG. 3, the water to be treated flows in through the conduit section 20 and arrives radially through the shell 23 of the conduit section 20 into the first electrode chamber 21.2. Then the water flows through the liquid-permeable insulating body 50 and reaches the second electrode chamber 21.1. From here the water reaches the conduit area 24 through the shell 23 the same way as in the embodiment in accordance with FIGS. 1 and 2.

[0030] Basically, the device in accordance with FIG. 3 is identical to the device in accordance with FIGS. 1 and 2. There is only a different arrangement of the electrodes 22.1, 22.2 and of the electrode chambers 21.1, 21.2.

[0031] Initially, the electrodes 22.2 can be negatively polarized in the electrode chamber 21.1. Accordingly a calcite precipitation occurs in the bulk material kept in the electrode chamber 21.1. The water then flows through the second electrode chamber 21.1 and flows off via the shell 23. A polarization change occurs after a defined period of time. The electrodes 22.2 then are positively polarized, the electrodes 22.1 negatively. Now the calcite precipitation occurs in the bulk material of the electrode chamber 21.1. During this state of the polarization, the calcite deposited on the carbon particles of the bulk material in the electrode chamber 31.2 is removed and flushed out with the water to be treated. A change in polarization again takes place after a defined length of time.

[0032] In accordance with this invention, a polarization change of more than 30 seconds provides good efficiency. If a shorter period of time is used, the effectiveness is reduced and with it the efficiency of the device.

[0033] Thus, it may be advantageous to employ an electronic switching device for controlling the polarization-reversing process. In this case the individual flow-through times should be added when the water removal occurs in a clocked manner. A polarization reversal then occurs only after the preset total interval length.

[0034] A flow meter can be used for optimizing the operation. The flow meter determines the amount of water which flows through and is to be treated continuously or at time intervals. The treatment current strength is then regulated as a function of this determined value. A flow meter can also be used alternatively or in addition as an indicator of the time for maintenance. A signal is emitted as soon as a defined amount of water is registered, which indicates the need for replacing the granular bulk material.

[0035] For being able to make determinations regarding the wear state, it is possible to integrate a measuring apparatus in the device, which measures the conductivity of the granular bulk material.

[0036] In another embodiment of the device of this invention, two or more groups of electrodes (22.1, 22.2) are formed. Initially, only one of the groups is operated until it is no longer sufficiently functional because of aging and/or output. Then a switch is made to a second group, or the latter is hooked up. 

1. A device for treating water, having a housing with conduit areas for conducting the water to be treated, wherein at least one first and one second electrode is arranged in the housing, wherein the first and second electrodes are alternatively positively and negatively polarized, and wherein an electrically conductive bulk material has been placed into the housing, characterized in that the first and second electrodes (22.1, 22.2) are housed in first and second electrode chambers (21.1, 21.2), which are separated from each other and are electrically insulated from each other by means of one or several insulating bodies (50), each of the electrode chambers (21.1,21.2) is filled by bulk material consisting of a uniform granulate, and the insulating bodies (50) are permeable to the water to be treated, but impermeable to the granulated bulk material.
 2. The device in accordance with claim 1, characterized in that the bulk material is a fixed bed electrode consisting of carbon granules.
 3. The device in accordance with claim 1 or 2, characterized in that the insulating bodies (50) are embodied as bulkhead walls and have a screen-like passage area for the water to be treated, wherein the opening sizes of the openings constituting the passage areas are less than the granule diameters of the particles of the bulk material.
 4. The device in accordance with claims 1 to 3, characterized in that the first and second electrodes (22.1, 22.2) are embodied rod-like and are surrounded over their entire length by the bulk material.
 5. The device in accordance with one of claims 1 to 4, characterized in that a conduit area (20) which is surrounded by an area which receives the electrode chambers (21.1, 21.2) is arranged in the housing (25), the conduit area (20) is in spatial connection with the electrode chambers (21.1, 21.2) via the openings, the side of the electrode chambers (21.1, 21.2) which faces away from the conduit area (20) in the radial direction is covered by means of a liquid-permeable shell (23), and a conduit section (24) adjoins the shell (23) in the housing (25).
 6. The device in accordance with one of claims 1 to 5, characterized in that the electrode chambers (21.1,21.2) are separated from each other by insulating bodies (50) which substantially extend in the flow direction of the water to be treated.
 7. The device in accordance with one of claims 1 to 6, characterized in that the electrode chambers (21.1, 21.2) are separated from each other by insulating bodies (50) extending transversely in respect to the flow direction of the water to be treated, and the electrode chambers (21.1, 21.2) are arranged one behind the other in the flow direction.
 8. The device in accordance with claim 7, characterized in that viewed in the flow direction, an oxidation zone, through which the water treated in the associated electrode chamber (21.1, 21.2), or in several electrode chambers (21.1, 21.2), is conducted, is arranged behind at least one of the electrode chambers (21.1, 21.2).
 9. The device in accordance with one of claims 1 to 8, characterized in that different volume flows of the water to be treated flow through the electrode chambers (21.1, 21.2) of different polarization.
 10. The device in accordance with one of claims 1 to 9, characterized in that the length of polarization of the cathodic and the anodic phases of at least one of the electrodes (22.1, 22.2) is selected to be different.
 11. The device in accordance with one of claims 1 to 10, characterized in that the electrodes (22.1, 22.2) are arranged at least partially concentrically in respect to the conduit area (20) arranged in the housing (25), and the electrodes (22.1, 22.2), which are arranged on a graduated circle around the conduit area (20) are distributed equidistantly in respect to each other in the ambient direction.
 12. The device in accordance with one of claims 1 to 11, characterized in that the water to be treated flows through a magnetic treatment device prior to entering the housing (25). 